Means for admitting air to a fire box



Feb 6, 1934. N. M. LOWER 4 MEANS FOR ADMITTING AIR TO A FIRE BOX Filed June 1l, 1931 ffii! rllllllllllllll'l' Patented Feb. 6, 1934 MEANS FOR ADMITTING AIR TO A BOX vFmr:

Nathan M. Lower, Baltimore, Md., assigner to The Standard Stoker Company, Incorporated, a corporation of Delaware Application June 11, 1931. seria1No.54s,555

4 Claims.

This invention pertains to the improvement in the structure of appliances adjacent the firing opening of a rebox, and particularly to improvement in the construction of parts thereof which form closures for the firing opening, which are exposed to the heat of the rebox, and are air cooled; such as, redoors and the delivery end of a Stoker.

One of the objects is to permit entrance of air 10. through the iiring opening into the rebox above the elevation of the rebed for the purpose of cooling the fuel distributing apparatus of a Stoker and firedoors, and to prevent emission of gases and other elements of the firebox through the firing opening by providing a one way valve or damper in the air passageways actuated by the draft and products of combustion in the rebox to automatically open and close the pas- Sageways.

With the present method of cooling redoors and the distributor plate of a Stoker relatively cold air is drawn through holes in the redcors and through a passageway between the lower margin of the firing opening and Stoker parts, respectively, by the draft inthe flrebox, and in the event of minor explosions and other disturby ances inthe rebox from Some unforseen defect or reason, such as caused by the breaking of an arch pipe or water tube in the case of a rebox 30 of a boiler, gases, flaming cinders, smoke, steam and hot water are dischargedthroughthe firing opening causing damage and probably injuryto persons in the vicinity thereof; and it is a further object of this invention to provide a construction that will correct this undesirable feature and prevent damage and casualties in the case such disturbances occur.

Other objects, advantages and novel details of construction will be apparent during thecourse of the following description taken in connection withV the accompanying drawing, inwhich:

Fig. 1 is a vertical sectional view taken on the center line of a Stoker firing opening of a stationary iirebox and a portion of a Stoker, showing one form of the invention as applied thereto.

Fig. 2 is a vertical transverse sectional view oi the structure shown in Fig. 1, taken online 2-2 thereof.

Fig. 3 is a vertical longitudinal sectional view .50 takenl on the center line of a common hand and Stokerl ring opening of a locomotive rebox showing a redoor and a portion of a Stoker with parts thereof broken away, illustrating a modified form of the invention as applied thereto.

Fig. 4 is a vertical transverse sectional view of Prier:

the .structure shown in Fig. 3, taken on line 4-4 thereof, with parts omitted.

Fig. 5 is a vertical sectional view of a redoor equipped with this invention, and is partly diagrammatic.

In Figures 1 and 2, the numeral 1, designates a brick wall of a irebox of the stationary boiler, heating plant, and steamboat type; 2, the Stoker firing opening therein; and 3, the stoker as a whole. inserted in the rlr oval Shaped metal ring 4 for ing opening 2 is an 65` supporting Athe bricks above the opening and preventing the bricks adjacent the opening from b ring 4 is provided with an ecoming loose. The outwardly extending flange 5 by which it is secured to the outside of 701 the firebox wall. A Stoker conduit 6L is butted against the ange 5, in alinement with the top margin of the ring 4, and is secured thereto. A jet plate casting 7 is supported upon the lower margin of the ring 4 andsecured to the Stoker 75- conduit so as to form a continuation of the lower. inside surface of the conduit. The jet plate 'I has iiuid nozzles 8 at the rebox end thereof in communication with a cored chamber 9. The

cored chamber 9 extends tr ansversely of the jet 801Y plate at the rebox end thereof and along the sides of the jet plate, as is apparent in Fig. 2. The cored chamber 9 communicates with a source of pressure by-means of suitable piping (not shown), which is well known in the art. A distributor table l0 is positioned in the reboxll, beneath and immediately forward ofthe :duid

nozzles 8, and supported on the Ylaterally project- 13. The positions of these manually by hand Wheels 56 Between the lower margin underside of the jet plate 7, of,`is an air passageway 14 outside of the flrebox to the inside.

vanes are controlled of the ring 4 and the and centrally thereextending from the The pas' sageway V14: is angular in shape, the portion 15 thereof extending'through the firing opening being horizontal; and the portion 16, which is outside of the rebox, being vertical. The jet plate 'Tis provided with three downwardly extending wallsA 17 .which formv the vertical the air passageway.`

Positioned inthe passage portion` 16 of way 14 is a. one way 1-19 valve or damper 18, which is hinged to the underside of the jet plate 7. The damper 18 is arranged to swing only in a direction to admit relatively cold air into the iirebox. Stops 19 on the sides 20 of the passageway prevent the damper from swinging in a direction to allow emission of elements from the rebox.

When the rebox has a fire therein the variation in pressure on opposite sides of the damper 18, due to the draft in the rebox, causes theY damper to swing toward the inside of the rlrebox and air enters the passageway 14 at the outside end thereof, is drawn through the firing opening, and directed to impinge upon the stoker parts that are exposed to the heat, for cooling;` the said parts. If a disturbance occurs in the rea box, causing the pressure on., the firebox side of the damper to become equal` to or greater than atmospheric pressure on the outside4A Of. the damper, the damper will close and prevent the escape of elements of the rebox through the pas.- sageway; and in case of a minor explosion the damper will snap shut. If a small percentage of thek discharge should get past the damper, the walls 17 will direct the discharge downwardly.

. Referring to Figures 3v and 4, the numeral 21 represents the rebox of a locomotive; 22, the back wall of theV iirebox having a common hand and stoker firing opening 23 therein; 24, the nredoor; 25, the locomotive cab; 26, the cab deck; and 27 the stoker as a whole. The flredoor 24 is attached to the backhead and closes the upper portion of the ring opening 23. The stoker 27 has laterally projecting flanges 28, by which it is rigidly secured to the backhead in the well known manner with studs 29. extending through these flanges; and it is apparent that the stoker closes the remainder of the firing opening 23 beneath the redoor.

The stoker structureshown in Figures 3 and 4 is similar to that illustrated in Figures 1 and 2. The transfer conduit portion 30 of the stoker extends upwardly through the. cab deck 26 and has its outlet end opening inside the nrebox. A distributor table 31 is positioned in the i'lrebox and secured to the forward end of the stoker. Fluid nozzles 32, at the rear oi the distributing table31, are in communication with cored chambers 33 and a source of pressure as described in regard to Figures 1 and 2. Any preferable form of conveying means may be employed to convey and deliver fuel into the path of the uid blasts issuing from the nozzles 32, and hinged vanes 34 may be. used to direct the flow ofy fuel to the iiuid blasts.

The transfer conduit portion 30. of the stoker is spaced from the lower margin of the firing opening 23. suiiciently to provide an air passageway 35'- from the outside to the inside of the rebox. The. passageway isangular in shape, the rear portion 36 of which is parallel to the outside of the backhead. The passageway 35 is formed by the side walls 37, front and rear walls38, and top and bottom walls 39 and 40, respectively. Top wall 39 also forms a part of the transfer conduit portion 30. The side walls 37 and the f ront and rear Walls 38 form the rear portion 36 of the air pas-` sageway which extends below the cab deck 26.

Hinged on a horizontal axis in the. passageway 35 is the valve or damper 41, Itis provided with adjustments 42 so that the weight thereof beneath the. axis about which it rotates can be made slightly greater than the weightl of the portion above its axis. Thus, the damper will,l always maintain a vertical position unlessthereisa draft in the rebox and the pressure in the inclined portion 43 of the air passageway is less than atmospheric pressure on the outside of the rebox. If the damper 41 is in its vertical position the passageway 35 is closed.

When the locomotive boiler is in operation the draft inthe rebox 21 causes the damper 41 to move to its open position (shown in dotted lines in Fig. 3) in the same manner as described in regard to Figures 1 and 2, and relatively cold air enters the passageway 35 beneath the elevation of the cab. deck, is drawn through the passageway, and directed by the shape of the passageway to imL pinge on the distributor table 31 and other stoker parts exposed to the heat, for cooling the same. I fY from any cause whatsoever, the pressure in theinclined portion 43 of the passageway becomes greater than the air pressure in the rear portion 36, the damper will immediately return to its vertical or closed position and prevent passage of elements from, the. rebox to` theY outside. Should a small percentage of the discharge leak past the damper 41, it will be directed downwardly beneath the cab deck; thus, probable` injury tothe fireman and engineer, and damage to apparatus in the cab is prevented.

It will be advantageous in some instances to regulate the amount of air that is admitted through the firing opening, as cold air admitted above the rebed causes neilicient combustion. To obtain this result a plurality of holes 4.4 are drilled radially about the axis of the damper, and. a pin 45, which can readily be withdrawn, is inserted in any one of the holes so that the d esired amount of air will be admitted to cool the parts exposed to the heat. The pin 45 acts as a stop for the damper and limits the open position thereof.

In Figure 5 the numeral 46 designatesV the back wall of a rebox; 47, the ring opening therein; and 48, the redoor as a unit. The iiredoor 48, comprises the fluid pressure actuated motorV 49., the main body portion of the redoor 5.0, the perforated renewable barile plate 5 1, and the baffle plate. securing bolt 52. Provided in the body portion of theredoor, near the upper end thereof, is an opening or passageway 53. Pivotedv in the body portion 50, adjacent the upper end of the passageway 53, is a valve ordamper 54-sim-ilar to the damper 41 shown in Figures 3A and 4. A stop 55,limits the open position of the damper 5 4.

Whenk there is a fire in the iirebox the. variation in pressure onV opposite sides ofthe damper 54 causesit to open and admit air to the` passage-` way 53 tov cool thebaffle plate 51 and other- Dalits of the` firedoor exposed tol the heat. When the pressure on the inside or rebox side of. the, ree door isv equalto. or greater than atmospheric pressure on theoutside, thedampery 54 will maintain. a vertical position and close the passage-4 way 53; thus preventing any dischargeY from the iirebox .escapingthrough thei ring opening.

AlthoughY L have shown and described what. I believe is. the preferred embodiment andiinsialla tionsof my invention, I do not want tol be lirn-A i ited tothe construction or applications, Shown and described, except insofar as I have included such limitations within the terms of the. follow: ing claims.

WhatI claim as new and desire to` secure, by Letters Patent is 1. In combination, a furnace having anl upf. right wall provided withr a firing opening, a iloor extending horizontally. outwardly from said wall belowl the levetof'v said opening, astoker conduit mounted externally of the furnace and communicating with said opening, fuel distributing means associated with the forward end of said conduit, said conduit arranged with the lower marginal edge of the nring opening to provide a space therebetween, and a casing surrounding said space interposed between said conduit and the upright wall of the furnace and extending downwardly to said iioor, said casing providing a passageway open only at its opposite ends, the one end opening adjacent the lower rearward end of said fuel distributing means and the other end opening to atmosphere below said floor, whereby the draft in the furnace will draw a current of air through said casing for cooling the forward end of said stoker conduit and said fuel distributing means.

2. In combination, a locomotive having a firebox provided with a backwall having a firing opening, a cab iioor rearward of said backwall, a Stoker conduit mounted externally of the rebox and communicating with said opening, fuel distributing means associated with the forward end of said conduit, said conduit arranged with the lower marginal edge of the firing opening to provide a space therebetween, and a casing surrounding said space extending through the cab floor, said casing providing a passageway open only at its opposite ends, the one end opening adjacent the lower rearward end of said fuel distributing means and the other end opening to atmosphere exteriorly of the cab, whereby the draft in the furnace will draw a current of air through said casing for cooling the forward end of said stoker conduit and said fuel distributing means.

3. In combination, a furnace having an upright wall provided with a firing opening, a floor extending horizontally outwardly from said wall below the level of said opening, a Stoker conduit mounted externally of the furnace and communieating with said opening, fuel distributing means associated with the forward end of said conduit,

said conduit arranged with the lower marginal edge of the firing opening to provide a space therebetween, a casing surrounding said space interposed between said conduit and the upright wall of the furnace and extending downwardly to said iioor, said casing providing a passageway open only at its opposite ends, the one end opening adjacent the lower rearward end of said fuel distributing means and the other end opening to atmosphere below said floor, whereby the draft in the furnace will draw a current of air through said casing for cooling the forward end of said stoker conduit and said fuel distributing means, and a damper for preventing the outward discharge of elements from the furnace through the passageway.

4. In combination, a furnace having an upright wall provided with a firing opening, a stoker conduit mounted externally of the furnace and communicating with said opening, fuel distributing means associated with the forward end of said conduit, said conduit arranged with the lower marginal edge of the firing opening to provide a space therebetween, a casing surrounding said space interposed between said conduit and the upright wall of the furnace to provide an angularly shaped passageway open only at its opposite ends, the one end opening adjacent the lower rearward end of said fuel distributing means and the other end opening to atmosphere exteriorly of the furnace, whereby the draft in the furnace will draw a current of air through said casing for cooling the forward end of said stoker conduit and said fuel distributing means, and a damper in the passageway for preventing outward discharge of elements from the furnace through the passageway actuated when there is a variation of pressure on opposite sides thereof, said damper being mounted to swing about an axisv intermediate its ends and arranged to assume a vertical position to close the passageway.

NATHAN M. LOWER. 

